<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>函数的定义与调用</title>
</head>
<body>
<script>
    function getSum() {
        var sum = 0;
        for (var i = 1; i <= 100; i++) {
            sum += i;
        }
        return sum;
    }
    document.write("1 到 100 之间所有整数的和为：" + getSum());
</script>
</body>
</html>